Coulomb's Laws

The positive permittivity of the dielectric means is represented as-

Two protons move parallel to each other, keeping distance r between them, both moving with same velocity $\overrightarrow{\text{V}}$. Then the ratio of the electric and magnetic force of interaction between them is

The force of interaction between two charges$q_1=1 \mathrm{\mu C}$and $q_2=3 \mathrm{\mu C}$ placed at a separation is $r$ is$10 \mathrm{N}$. Then force of interaction between two charges$q_3= 2 \mathrm{\mu C}$ and $q_2=3 \mathrm{\mu C}$ , placed at a separation $r$, is

Determine the electric field intensity at point P due to quadruple distribution shown in figure for $r\gg a$.

Two point charges $-q$ and $+2q$ are placed at a certain distance apart in the same order. Where should a third point charge be placed so that it is in equilibrium?

According to Coulomb's law, which is the correct relation for the following figure?

A charge $q$ is placed at the centre of the line joining two equal charges $Q$. If the system of charges be in equilibrium, then find minimum value of charge $Q$ from the given options. ($e\to$charge of an electron)

Force of attraction between two point charges $Q$ and $-Q$ separated by $d \mathrm{metre}$ is $F_e$. When these charges are placed on two identical spheres of radius $R=0.3d$ whose centres are $d \mathrm{metre}$ apart, the force of attraction between them is

Four charges are at the corners of a square as shown in the figure. Corners A and D have equal charge, while both B and C have a charge of $+1 \mathrm{C}$. What is the charge on A so that the force on B is zero?

A $10 \mu \mathrm{C}$ charge is divided into two parts and placed at $1 \mathrm{cm}$ distance so that the repulsive force between them is maximum. The charges of the two parts are:

A $10 \mathrm{\mu C}$ charge is divided into two equal parts and kept at $1 \mathrm{cm}$ distance. Find repulsion between charges?

Which of the following statement is correct?

If the distance between two charges become double, then electrostatic force between them will become 

In the figure, if net force on $Q$ is zero then value of $\frac{Q}{q}$ is

The force between two charges $0.06 \mathrm{m}$ apart is $5 \mathrm{N}$. If each charge is moved towards the other by $0.01 \mathrm{m}$, then the force between them will become 

According to Coulomb's law, which is the correct relation for the following figure?

The order of magnitude of minimum electrostatic force between two charge particles at a separation of 1m is

$\sqrt{3}\times {10}^{-19} \mathrm{C}$ and $-{10}^{-6} \mathrm{C}$ are placed at $\left(0,0,0\right)$ and $\left(1,1,1\right)$ respectively. The force on the second is of the form